1. Field of the Invention
The present invention relates to a high-frequency surgical apparatus and high-frequency surgical method for closure of patent foramen ovale, the apparatus and method being used to treat patent foramen ovale (PFO) in the heart.
2. Description of the Related Art
There is a condition known as patent foramen ovale (PFO). The PFO is a flaplike opening in part of the atrial septum which separates the left atrium from the right atrium in the heart. Normally, the pressure in the left atrium is higher than the pressure in the right atrium, closing the patent foramen ovale by pressing it into contact with the atrial septum. However, severe coughing or tension (due to pressure on the lungs) can reverse the pressure difference, temporarily opening the flap.
Blood may contain blood clots developed in the body. Normally, the blood returning to the right atrium from the body is sent to the lungs where any blood clot is removed. However, it may happen that the instant the PFO opens, a blood clot passes through the PFO and sent back to the body. If the blood clot reaches the brain, it can cause cerebral infarction. To prevent cerebral infarction, it is desirable to close the PFO.
For example, PCT International Publication No. WO 2007/100067 discloses a high-frequency surgical apparatus which closes a PFO using high-frequency power. The conventional example involves grasping a PFO by grasping means which includes a needle member and grasping member, applying high-frequency power to the needle member and grasping member serving as high-frequency electrodes, and heating and closing the PFO by Joule heating.